Hi,
I have towed my 2006 Sport behind my MH for many years. The Libby is pretty much the perfect toad - no fuss, ****** in Park, transfer case in N, steering unlocked = done. I only have ~60k on the odometer, but there is a bit over 90k towed. Room for 4 adults and some room for "stuff" in the rear. Keep in mind that you need to track milage differently: odometer for engine related items (oil changes, brakes, etc.) and towed miles for running gear related items (tires, diff fluid, etc.). I ruined a new set of BF Goodrich Rugged Terrain tires on a trip to Alaska because I neglected to rotate the tires half way through the 9500 mile trip. They were badly cupped in the front and started making a loud whine/hum.
As far as tires, a good set of all-terrains in stock size should do very well for you. With the Rugged Terrains and later General Grabbers we had no problems with several inches of snow in and around Boise, the beach on the Outer Banks of NC. trails in Death Valley, Shafer trail in Moab, and trails in Grand Staircase, Utah.
I found headlights and turn signal indicator lens on eBay.
BTW, you will need to get an auxiliary braking system for the Libby. I use a RVI Brake II - its portable so I can use it in my other toad. People will say there is no need for an auxiliary brake. I have towed over 100k miles and have had at least a half dozen instances where the auxiliary brake prevented me from rear ending another vehicle in panic stops. Not only is it the law in all lower 48 + Alaska, it's just plain common sense. My Libby weighs ~3800 lbs, enough to push my 30k lb. MH when stopping. Think an additional 10%+ rolling weight. As you probably know driving a MH is "interesting" people do not like to follow you and will dive in front of you in a moment. Leaving extra stopping room is a have to do practice, but often it is taken as an invitation to merge in front.
Good luck with your new to you Libby and safe travels,